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991.
992.
日粮纤维的营养学功能及对母猪产仔数的影响   总被引:1,自引:0,他引:1  
母猪繁殖性状主要包括总产仔数、产活仔数、初生个体均重及初生窝重、泌乳力、断奶仔猪数、断奶个体均重及断奶窝重,其中,产仔数是最重要的繁殖力评定指标。日粮纤维对家畜的营养物质的消化率存在负面影响,但是近半个世纪以来由于日粮纤维独特的性质在母猪的营养研究中备受关注。文中将从日粮纤维的定义及分析方法、理化特性着手,阐述日粮纤维添加到母猪妊娠日粮中对产仔数的影响并分析其可能原因。  相似文献   
993.
厚朴林下轮作玄参、大黄种植技术研究   总被引:1,自引:1,他引:0  
为更好地指导厚朴规范化种植,充分利用土地资源,大力发展林下经济,增加农民收入。2002年,在龙坪乡开展了厚朴林下轮作玄参、大黄种植模式和厚朴单作种植模式对比试验研究。试验结果表明:在厚朴林下轮作玄参、大黄种植模式下,厚朴各测树因子及皮产量较对照具有明显地增长和增产作用,同时每个轮作期内比对照增产大黄药材520 kg/666.7 m2、玄参药材320 kg/666.7 m2。  相似文献   
994.
利用Arcgis地理信息系统平台,运用空间分析技术手段,以湖北襄阳鹿门寺景区地形图和卫星影像等数据为基础,选择不同观测点进行视域分析,设定了景区林火视频监控摄像头的位置,为森林防火管理辅助决策提供了依据。  相似文献   
995.
A total 61 clone parents and 320 open-pollination progenies from 8 clone individuals were identified by 12 polymorphic SSR loci.The result showed that the level of genetic diversity in progeny population was the same as in maternal population, progeny population had all alleles detected in maternal population,and there were not obvious surplus phenomenon of homozygotes in progeny population (F= 0.046).The south crown had more strobili than the north crown,however the genetic diversity of the north crown strobili was not substantially reduced.The progeny of neutral trees had the same level of genetic diversity as in the progeny of partial female trees,with the fixation index tended to be zero,which was accorded with Hardy-Weinberg equilibrium.The multilocus outcrossing rate in the seed orchard was 1.097,and there was no significant inbreeding between parents(t_m-t_s= - 0.031).The multilocus outcrossing rate and singlelocus outcrossing rate in the south crown were higher than that in the north crown.The multilocus outcrossing rate of partial female trees was the same as in neutral trees,and the neutral tree had no obvious declining outcrossing rate with reduced proportion of female and male strobilus compared with partial female tree, with the fixation index tended to be zero.The progeny of the second generation clonal seed orchard still had rich genetic diversity,gene exchange among clones was relatively sufficient,and biparental inbreeding was not significant.  相似文献   
996.
于2010~2011年在西宁市主要地表水体设12个断面,对10项水质指标进行了监测和分析。结果表明:氨氮和总硬度严重超标,远高于GB3838-2002《地表水环境质量标准》中Ⅲ类标准;铁、化学需氧量(COD)、挥发酚、总氯、电导率、六价铬、pH值符合GB3838-2002《地表水环境质量标准》中Ⅲ类标准浓度限值;个别断面平水期、枯水期的溶解氧(DO)浓度略低于GB3838-2002《地表水环境质量标准》中Ⅲ类标准浓度限值。  相似文献   
997.
猪附红细胞体病是由支原体目中的附红细胞体引起猪的一种以急性黄疸性贫血和发热为特征的传染病。又称为黄疸性贫血、红皮病。1972年在我省南部报道猪红皮病,后来被证实为猪附红细胞体病。随着我国规模化养猪业的发展,疾病的复杂程度加大,猪附红细胞体病也成为养猪生产中的突出问题,最近几年来,该病在我市常有发生,给我市的养猪业造成了一定的经济损失,成为养猪生产中的常发病和继发病。  相似文献   
998.
We have completed the genetic characterization of all eight gene segments for four low pathogenic avian influenza (LPAI) viruses. The objective of this study was to detect the presence of novel signatures that may serve as early warning indicators of the conversion of LPAI viruses to high pathogenic avian influenza (HPAI) viruses. This study included three H5N2 and one H5N3 viruses that were isolated from live poultry imported into Singapore as part of the national avian influenza virus (AIV) surveillance program. Based on the molecular criterion of the World Organisation for Animal Health (OIE), sequence analysis with the translated amino acid (aa) sequence of the hemagglutinin (HA) gene revealed the absence of multibasic aa at the HA cleavage site, identifying all four virus isolates as LPAI. Detailed phylogenetic tree analyses using the HA and neuraminidase (NA) genes clustered these isolates in the Eurasian H5 lineage, but away from the HPAI H5 subtypes. This analysis further revealed that the internal genes clustered to different avian and swine subtypes, suggesting that the four isolates may possibly share their ancestry with these different influenza subtypes. Our results suggest that the four LPAI isolates in this study contained mainly avian signatures, and the phylogenetic tree for the internal genes further suggests the potential for reassortment with other different circulating avian subtypes. This is the first comprehensive report on the genetic characterization of LPAI H5N2/3 viruses isolated in South-East Asia.  相似文献   
999.
The suitability of certain commercial and self‐made chemically defined extenders for liquid storage of goat semen was tested and the effects of storage temperatures, dilution rates and sperm washing and pH of extenders on the goat sperm during liquid storage were observed. Semen was collected from nine goat bucks of the Lubei White and Boer breeds using an artificial vagina. Each ejaculate after initial evaluation was diluted with a specific extender, cooled and stored at a desired temperature. Stored semen was evaluated for sperm motility and other parameters every 24 or 48 h of storage. The ranking order of the existing milk‐ and yolk‐free extenders in sustaining goat sperm motility was Androhep > Zorlesco > Beltsville thawing solution > the Tris–glucose medium. The new extender (mZA) which was formulated based on Zorlesco and Androhep was more suitable for goat sperm than Androhep. The mZAP extender with Bovine Serum Albumin (BSA) replaced with polyvinyl alcohol (PVA) worked as efficiently as the mZA in maintaining sperm motility, membrane integrity, acrosome intactness and capacitation status. Goat sperm motility was best maintained at 5°C during liquid preservation, but decreased significantly as the temperature increased. When semen was sixfold diluted, sperm motility was maintained longer (p < 0.05) after centrifugation, but sperm motility did not differ between the centrifuged and non‐centrifuged groups when semen was 11‐fold diluted. When the extender pH was adjusted from 6.6 to 6.04, the efficiency increased significantly in both Androhep and mZAP. A forward sperm motility of 34% was maintained for 9 days when buck semen was 11‐fold diluted and stored at 5°C in mZAP, with pH adjusted to 6.04. It is concluded that for liquid storage of buck semen, the mZA extender was more suitable than other extenders; BSA can be replaced with PVA in mZA; centrifugation to remove seminal plasma can be omitted by adequate dilution; and the storage temperature and pH of extenders affected sperm motility significantly.  相似文献   
1000.
<正>目前,国内外对现代企业设备管理的研究很多,成熟的理论和丰富的经验也不少。但当前我国饲料企业设备管理的实际情况与其他如电子、机械等行业大有不同,再先进的设备管理模式也不一定能很好地适合饲料企业的实际。本文在分析当前我国饲料企业设  相似文献   
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